Fastener applying implement



June 2, 1959 H. F. PETERSSEN ET AL ,8

FASTENER APPLYING IMPLEMENT s Sheets-Sheei 1 Filed Sept. 10, 1957 v INVENTORS HENRY F. PETERSSEN EDWARD LFISHER BY Wag:

ATTORNEYS June 2, 1959 H. F. PETERSSEN ET AL 2,883,679

FASTENER APPLYING IMPLEMENT Filed Sept. 10, 195'? s Sheets-Sheet 2 if a I J 53 i w r. 2 i

5 INVENTORJ' HENRY F. PETERSSEN EDWARD I. FISHER ATTORNEYS J 1959 H. F. PETERSSEN ET AL 8 ,5

FASTENER APPLYING IMPLEMENT Filed Sept. 10,- 1957 5 Sheets-Sheet 3 INVENTORS HENRY F. PETERSSEN EDWARD l. FISHER ATTORNEYS United States Patent FASTEN ER APPLYING IMPLENIENT Henry F. Peterssen and Edward I. Fisher, Westerly, R.I.,

assignors to Bostitch, Inc., Stonington, Conn., a corporation of Rhode Island Application September 10, 1957, Serial No. 683,067

12 Claims. (Cl. 144.4)

This invention relates to fastener-applying devices and more particularly to a portable fluid-pressure operated implement for fastening upholstery fabrics to the interior of automobile bodies, to furniture and the like, or for attaching numerous other articles to various objects.

One object of the invention is to provide a relatively light-weight compact implement that may be held conveniently in one hand and manipulated for operation in different positions to apply fasteners, such as U-shaped wire staples, in constricted spaces.

Another object is to provide an implement of the type indicated in which the fastener-driving means is operated in such manner as to prevent the fasteners from tearing, abrading or otherwise damaging the material through which they are driven.

Another object is to provide means for operating the fastener-driver with an initial relatively slow motion increasing in force to separate a staple from the supply stick and finally continuing its motion under momentum to drive a staple with the power-actuating force discontinued.

Another object is to provide in an implement of the type indicated a reciprocable piston having a head for receiving the pressure, a plunger separate from said piston but arranged to be driven thereby, and a fastenerdriver connected to said plunger for operation to drive a fastener into the work.

Another object is to provide manually-operable valve means for applying the pressure to the piston in progressive stages to initiate its motion at slow speed, gradually increase the force and finally disconnect the force therefrom whereby the plunger-driver continues its motion under momentum for setting a fastener in the work.

Another object is to provide means for cushioning the shock on the piston as it is arrested at the end of its stroke and releases the driver to continue its motion under momentum for setting a staple in the work.

Another object of the invention is to provide an extremely simple and eflicient mechanism for actuating the fastener-driver by the improved method described, and comprising a minimum number of elements of novel construction and arrangement adapted for economical manufacture and not liable to excessive wear or dislocation.

Further objects of the invention are set forth in the following specification or will be understood by those skilled in the present art; it being understood that the present disclosure is by way of example to illustrate a preferred embodiment of the invention with one alternate form of construction.

The following description of the invention is illustrated by the accompanying drawings, in which:

' Fig. 1 is a side elevational view of the implement shown partly in longitudinal section in a plane interjsecting the vertical axis of its pressure cylinder and piston;

Fig. 2 is a similar view with the parts shown complete- ,;ly in section in the same axial plane and illustratingthe piston and driver during their descent under maximum pressure;

Fig. 3 is a sectional view similar to Fig. 2, showing the piston and driver at the end of a downward stroke for driving a fastener;

Fig. 4 is a top plan view of the column containing the cylinder in which the piston reciprocates, showing the upper closure or cover as partly broken away;

Fig. 5 is a transverse sectional view through the column and cylinder taken on line 5-5 of Fig. 1;

Fig. 6 is a bottom plan view at the forward end of the magazine showing the mounting for connecting the column and cylinder to the magazine;

Fig. 7 is a disassembled view in perspective of the reciprocable plunger, the fastener-driver connected thereto, the piston for operating said plunger, the inner annular element connecting the plunger to the piston for operation thereby, and the spring for raising these elements after driving a fastener; and

Fig. 8 is a vertical sectional view of the cylinder showing an alternate form of construction of the piston and plunger and their associated parts.

In general, the present improved fastener-applying machine or implement is similar to that described in a copending application for United States Letters Patent, Serial No. 649,833, filed April 1, 1957, now Patent No. 2,857,596, dated October 28, 1958, and comprising a longitudinally extending magazine for staples surmounted at its forward end by a vertical cylinder containing a fluid pressure-operated piston for reciprocating the stapledriver in a throat that receives the staples fed from the magazine. The magazine of the present machine may be of any desired form or construction and as herein illustrated it is of the rear-loading type substantially identical to that shown in the aforementioned patent application. Suflice it to state therefore, that the magazine 2 is of conventional U-shape with an inner core 3 on which the staples are slidably mounted to be fed forwardly into the throat by a usual form of pusher 5 under the impulse of a spring 6.

The forward end of the magazine 3 is provided with a nose 7, so-called, in which is a slotted throat 8 for receiving the staples s and providing a raceway through which they are driven in applying them to the work. The front of the throat 8 is normally closed by a removable door 10 held in place by a pivotally mounted bow-shaped spring 11 engaging it at the top and bottom as shown and described in the aforementioned application. A cam-shaped rod 12 rotatably mounted at the front of the door 10 has a lever 15 at one end for manually rocking it to engage its cam-portion 16 with the spring 11 and compress it for binding the door against the nose 7 on the magazine. The spring 11 may be manually released for removing the door or closure 14) to provide for clearing the machine of malformed staples that may become caught or jammed in the throat 8. It is to be understood, however, that other forms of construction of these last described parts may be applied to use with the present invention.

The forward end of the magazine 2 has fastened to its sides by welding or otherwise a pair of sheet-metal plates 17 (Figs. 1 and 6) formed at the. top with rightangular lateral flanges 18 serving as a rest or support for a column 20. The column 20 may be constructed as a casting, or otherwise, with its base fastened to the lateral flanges 18 on the plates 17 by screws 21 or by other means such as welding. The column 20 is formed with an axial bore 22 for receiving a cylindrical tube 25 lining the bore and hereinafter designated, for convenience of description, as the fluid-pressure cylinder of the implement. The cylinder 25 is flanged outwardly at the assaere on bottom (Fig. l) to seat it against a disk 26 held in the bottom of the bore 22 and provided with an axial opening 27 of less diameter than the interior of the cylinder. The upper end of the cylinder is closed by a cap or cover 28 extending thereacross and fastened to the top of the column 29 by screws 29. On the under side of the cap 28 is a relatively thin circular boss 3%] projecting down into the cylinder 25 and serving as a stop for the piston 35, next described, as it reaches the end of its upward stroke.

Slidable in the cylinder 25 is a two-part piston 35 cornprising an outer annular cup-like member 36 having a fiat wall at the top with a depending cylindrical skirt fitting closely the interior wall of the cylinder. Mounted within the upper member 36 is an annular member 37 formed with a laterally projecting flange 38 at the bottom engaging against the lower rim of the skirt of the upper member 36. The member 37 is formed with an axial opening in its upper wall for receiving a plunger it; to which the staple-driver 45 is attached.

The plunger 40 has a fiat head 46 at its upper end adapted to overlie and engage the top of said member 37 with its lower shank-portion projecting downwardly beyond the two parts of the piston 35. The lower end of the plunger 4% is provided with an axially-extending slot 47 (Fig. 7) in which the staple-driver blade 45 is fastened by a cross-pin 48. The staple-driver 45 is thus connected to the piston 35 to be rcciprocated thereby in the throat 8.

A helical spring 58 seated on the disk 25 in the bottom of the cylinder 25 has its upper end engaging under the top wall of the inner member 37 for normally maintaining the piston 35 and driver 55 in raised relationship as shown in Fig. l. Seated on the disk 2-6 in the bottom of the cylinder 25 is a ring or annulus 52 constructed of rubber or other resilient material and resting thereon is a similar annulus 53 of plastic or like material that takes the thrust of the piston at the end of its descent with the rubber ring 52 acting as a butter to cushion the impact.

The upper end of the column 2% is formed with an integral handle-member 65 extending horizontally above and in parallel relation to the magazine 2. The handle 65 is of hollow construction throughout the greater portion of its length to provide an inner chamber 66 for the pressure fluid, preferably compressed air, supplied thereto at its outer end. For this purpose a hose 57 connected to a suitable source of compressed air, not herein shown, communicates with the airchamber 65 through a coupling 68 having a nipple 69 screwed into a threaded hole in the end of the handle 65. At the forward end of the chamber 66 in the handle 65 is a valvehousing 70 formed with a bore 71 enclosing a bushing 72 for slidably mounting the stem 74 of a poppet 75. The stem 74 of the poppet 75 is formed at the top with a circular head 76 adapted to seat in a counterbore at the upper end of the bore 71 in the housing 79 to close the valve.

The upper portion or" the stem 74 is reduced in diameter to give access to a port 77 at the end of an airpassage or channel 78 leading upwardly to an annular recess or passage 79 encompassing the cylinder 25. A plurality of openings or ports 84), herein shown as four in number spaced at ninety degrees around the wall of the cylinder 25, communicate with the interior thereof (Fig. 2) to apply the maximum pressure to the piston 35 after its downward stroke has been initiated by pressure through restricted passages at the top of the cylinder as later described. With the piston 35 raised to its uppermost limit (Fig. l) and normally retained in this relationship by contact with the stop or boss on the cover 28, a relatively small chamber 31 (Fig. l) of narrow confines is provided at the upper end of the cylinder 25. At this juncture the skirt of the piston covers the ports '80 and prevents ingress of pressure directly into the interior of the cylinder 25 so that the pressure is diverted upwardly to the restricted chamber 31 by means as next described.

Fitted within the cylindrical wall of the annular passage 79, previously mentioned, at the upper end of the column 25 is a ring or annulus 91? having a gasket 91 held in a groove in its interior face and bearing against the peripheral surface of the cylinder 25 for sealing the joint therebetween. Formed on the interior of the cylinder 25 at its upper end are a plurality of vertical slots 92 (Fig. 4) providing passages or ports leading from the annular recess 79 and communicating with the restricted chamber 31 thereabove to admit reduced pressure thereto above the piston 35.

The opening 27 in the disk 26 at the bottom of the cylinder 25 allows the air to exhaust therethrough during the descent of the piston 35 and provision is made for exhausting the air from the upper portion of the cylinder 25 when the piston 35 is raised by the spring 50. For this latter purpose the passage 73 that leads from the port 77 and connects with the ports communicates with a port 94 at the end of a passage 93 (Fig. 1) when the valve 75 is closed. The passage 93 leads from an opening or port 94 in the bushing 72 of the valve-housing 76 and extends downwardly to communicate with an opening 95 in the side of the cylinder 25 adjacent its lower end. After the piston 35 has reached the end of its downward stroke and starts to ascend due to closing of the valve 75 in the handle 65 (Fig. 1) pressure is exhausted from the upper portion of the cylinder 25 through the passages 78 and 93 and the openings 95 and 27. The valve 75 is operated manually by means of a trigger 97 formed with ears 98 pivoted on the ends of a pin 99 extending through the handle 65. The trigger 97 engages the rounded end of the stem 74 of the valve 75 and the valve is normally main tained closed (Fig. l) by the pressure in the air-chamber 66 acting against its head 76.

The method of operation of the complete implement is as next explained. After the magazine 2 has been loaded with staples s, connected in a strip or stic entered through its rearward end, the handle 65 is grasped and manipulated to place the nose 7 against the work; it being understood that compressed air has already been supplied to the chamber 66 through the hose 67 and coupling 63. The operator places his forefinger under the trigger 97 and presses it upwardly to open the valve 75 (Fig. 3) for admitting pressure through the passage 78 and into the annular passage 79. At the initial stage in the operation of the device the piston 35 is at the upper end of the cylinder 25 (Fig. l) beneath the restricted pressure-chamber 31 between its head and the cap 28. Consequently, when the valve 75 is opened pressure in the annular passage 79 will flow through the slots 92 at the upper end of the cylinder 25 to enter the restricted chamber around the boss 30 whereby to initiate downward movement of the piston 35 at relatively slow speed. As the piston 35 continues its downward motion under this limited pressure its skirt will gradually uncover and open the ports 80 to admit maximum pressure from the chamber 66 through the passage 78. As the ports 80 are fully opened the speed of the piston 35 will be accelerated for the remainder of its descent until finally its downward stroke is arrested as the inner element 37 strikes the annulus 53 (Fig. 3). As this eventuates the rubber ring 52 at the bottom of the cylinder 25 is com pressed slightly to cushion the impact.

During the downward stroke of the piston 35 under maximum pressure the staple-driver 45 descending therewith engages the foremost staple s in the throat or raceway 8 (Fig. 2) to separate it from the stick to which it is attached and drive it downwardly. Normally, the plunger 40 is suspended against the action of gravity (Fig. l) by engagement of its head 46 with the top of the element 37, but as the piston 35 descends and the end of the driver 45 strikes the staple s inthe throat 8 it is caused to apply a sharp blow thereon to separate said staple from the stick to which it is attached. Finally, as the piston comes to rest, the force of momentum will continue the downward stroke of the plunger 40 and driver 45 to an extent suflicient to set the staple in the Work without the full force of the piston exerted thereon. It will be observed further that due to the novel and ingenious construction and arrangement of the mechanism the plunger 40 and driver 45 are free to continue their stroke under momentum within the spring 50 without resistance or impedence by said spring.

In this way the machine is operated to drive the staples through the raceway 8 and set them in the Work with a yielding blow so as not to injure the material into which they are driven. Stated briefly, the present improved device provides for initiating the operation of the piston and staple-driver 45 at relatively slow speed, gradually increasing the speed to the maximum to a point where a sharp blow is struck to separate a staple from the stick to which it is joined and then continuing the driving action until finally the force of the piston is relieved and the staple-driver continues its stroke with a yielding action to avoid damage or injury to the material being operated upon.

After each staple has been driven into the work the trigger 97 is released to allow the poppet 75 to close under the pressure of the air in the chamber 66. Downward movement of the valve-poppet 75 opens the passage 93 leading to the opening 95 adjacent the bottom of the cylinder 25 to exhaust the air from the upper end of the cylinder 25. Then as the piston 35 starts to ascend under the force of the spring 50 bearing against the inner member 37 said member carries the plunger 40 upwardly as it engages under its head 46 and thereby the driver 45 is returned to initial relationship. As the piston 35 reaches the upper end of the cylinder 25 (Fig. l) the parts are restored to operative relationship in preparation for repeating the operation of driving another staple.

Fig. 8 illustrates a modified form of construction of the piston and plunger for reciprocating the staple-driver 45. In this alternative form of the invention the main element 100 of the piston is of inverted cup-shape with a cylindrical skirt 101 slidably engaging the interior wall of the cylinder 25. Closing the bottom of the main ele ment 100 is a separate element consisting of a relatively flat disk-like member 102 formed with an axial opening 103. A plunger 105 having an enlarged head slidably fitting the interior of the main element 100 has its head adapted to engage the upper wall thereof leaving a relatively narrow space above the member 102. The plunger 105 is formed with a reduced extension or shank 106 which is slotted axially for receiving the staple-driver 45 to fasten it thereto. With the enlarged head portion of the plunger 105 engaging the top Wall of the piston element 100 the space left between its lower edge and the closure 102 permits limited axial movement therebetween. With the parts in this relationship as shown in Fig. 8, pressure in the upper part of the cylinder 25 will cause the piston 100 to descend to carry the driver 45 downwardly. When, however, the motion of the piston 100 is arrested by striking against a stop, for example such as shown at 53 in Fig. 3, the plunger 105 will continue its stroke under momentum to complete the setting of a staple. After the driver 45 has completed the setting of a staple the spring 50 engaging under the member 102 Will raise the piston 100 and thereby the plunger 105 through its engagement therewith for returning the driver 45 to first position. It will be observed that certain parts of the piston as last described are of somewhat simplified construction and arrangement but adapted nevertheless to operate in the same manner to produce the same result as described in connection with the form shown in Figs. 1 to 3 of the present drawings.

It will be observed from the foregoing specification that the present invention provides aparticularly ingenious construction and arrangement of the operating elements in a fastener-driving implement or similar machine to secure the beneficial results set forth. Further, it will be seen that the device is of relatively simple construction, not liable to disorganization of its parts or getting out of order, and most efiicient in use for the purposes stated. It is to be understood that while the invention is herein shown and described in a preferred form of construction and one alternative form, further modifications may be made in the shape and relationship of the parts without departing from the scope of the invention as set forth in the accompanying claims. Therefore, without limiting ourselves in this respect, we claim:

1. In a fastener-applying implement, a cylinder, a piston reciprocable in said cylinder, means to supply fluidpressure to said cylinder to move the piston in one direction, a fastener-driver connected to said piston for reciprocation thereby, said fastener-driver constructed and arranged for limited movement in opposite directions axially of said piston, and a spring engaging directly with said piston independently of said fastenerdriver Without resistance to the axial movement of the driver relatively to said piston, said spring acting to return said piston to initial position after completion of its driving stroke.

2. In a machine of the type indicated comprising a reciprocable fastener-driver, a cylinder, means for admitting fluid-pressure into said cylinder, a piston slidable in said cylinder by the fluid-pressure, said fastenerdriver connected to said piston for limited movement in opposite directions axially thereof, and a spring engaging directly with said piston Without engagement with said fastener-driver whereby to permit free axial movement of said driver relative to said piston, said spring acting to return the piston to first position after a driving operation.

3. In a machine of the type indicated, a cylinder, a piston reciprocable axially in said cylinder, means to supply fluid-pressure to said cylinder to slide the piston in one direction therein, a fastener-driver reciprocable in said cylinder, means connecting said fastener-driver with said piston for reciprocation thereby, said fastenerdriver having limited movement in opposite directions axially of said piston, means for arresting the driving stroke of said piston while allowing the driver to continue its movement under momentum, and a spring engaging said piston independently of said fastener-driver for returning said piston to first position after said fastener-driver applies a fastener to the work.

4. In a machine of the type indicated, a cylinder, a piston slidable in said cylinder, means to supply fluidpressure to the interior of said cylinder for sliding the piston in one direction, a member connected to said piston for reciprocation thereby, a fastener-driver connected to said member for reciprocation therewith and freely movable to a limited extent axially thereof, means to arrest the driving stroke of said piston and allow said fastener-driver to continue its stroke under momentum, and a spring in said cylinder engageable directly with said piston for returning the piston to initial position after a driving stroke thereof'whereby to return said fastener-driver to inoperative position after applying a fastener to the work.

5. in a machine of the type indicated comprising a cylinder, a two-part piston slidable in said cylinder, means to supply fluid-pressure to said cylinder to slide the piston in one direction, means to connect the two parts of the piston to move together, a fastener-driver connected to one part of the piston for limited movement in opposite directions axially of the other-part of said piston, means to arrest the driving stroke of the piston and release said driver to continue its movement under momentum, and a spring engaging the piston independently of the fastener-driver for returning said piston and fastener-driver to initial relationship after the completion of a driving stroke for setting a fastener in the work.

6. In a machine of the type indicated comprising a cylinder, a piston having two parts connected to move together in sliding engagement with the inner wall of said cylinder, means to supply fluid-pressure to said cylinder to slide the piston in one direction, a fastenerdriver connected to one part of said piston for limited movement in opposite directions axially of said piston, means for arresting the operative stroke of said piston to permit said fastener-driver to continue its stroke under the force of momentum, and a spring engageable with said piston independently of said fastener-driver to return the piston to initial position after the completion of setting a fastener in the work.

7. A machine of the type indicated comprising a cylinder, a two-part piston having annular inner and outer elements arranged with one enclosing the other and connected to move together in engagement with the inner wall of said cylinder, means to supply fluid-pressure to said cylinder for sliding the piston in one direction, a fastener-driver mounted within said inner element of said piston for limited movement in opposite directions axially of said piston, means to arrest the motion of said piston to permit said fastener-driver to continue its stroke under momentum independently of said piston, and a spring engaging said piston for returning the piston and fastener-driver to initial position after the completion of setting a fastener in the Work.

8. In a fastener-applying implement comprising means for feeding fasteners and a reciprocable fastener-driver for driving the fasteners into the work, a cylinder, a piston reciprocable in said cylinder, power means for moving the piston in one direction, means connecting said fastener-driver to said piston for limited movement in opposite directions axially thereof, means for arresting the operative stroke of the piston, whereby said driver may be moved by momentum to extend its stroke beyond the range of the piston, and a spring engaging directly with said piston independently of the driver for returning the parts to first position after a driving operation.

9. In a fastener-applying implement comprising a raceway and means for feeding fasteners into said raceway, the combination of a cylinder connected to said raceway a two-part piston having each part engaging the inner wall of said cylinder and connected for unitary sliding movement therein, means for supplying fluid-pressure to said cylinder for sliding the piston in one direction, means engageable by said piston for arresting its operative stroke, a plunger connected to said piston for limited axial movement relatively thereto, a fastener-driver connected to said plunger for reciprocation in said raceway, said plunger being freely movable axially of said piston to a limited extent relatively thereto under the force of momentum to continue the movement of the driver after the piston comes to rest at the end of its stroke of predetermined length, and a spring engaging directly with said piston for returning the fastener-driver to inoperative position.

10. In a fastener-applying implement having a raceway and means for feeding fasteners into said raceway, the combination of a cylinder at one end of said raceway, means for supplying compressed air to said cylinder, a

- S piston comprising a hollow annmarme'mbe'r having a top wan'and a depe'nding cylindrical skirt slidably engaging the interior wall of said cylinder, a second annular member engaging the interior wall of the first annular member with a peripheral flange at the bottom thereof engageable with the end of the cylindrical skirt of the first annular member to connect said members to move together as a unit, said inner member having an axial opening in its upper wall, a headed plunger slidable in said opening with its head engageable with the top wall of the inner annular member and axially movable relatively to both members for engaging the upper wall of the outer member, a fastener-driver connected to said plunger, and a spring mounted in said cylinder and engageable with said inner member for raising said plunger and thereby the piston to reverse the stroke of said driver.

11. In a fastener-applying implement comprising a raceway and means for feeding fasteners into said raceway, a cylinder mounted above said raceway, a two-part piston comprising an annular member having a top wall with a depending cylindrical skirt engaging the interior wall of said cylinder, means for supplying fluid-pressure to the end of said cylinder for sliding said piston downwardly, an inner annular member fitted to the interior of the first-named annular member and having a top wall with an axial opening therein and an annular flange at the bottom engageable with the rim of the skirt of said first-named annular member, a plunger slidably mounted in said axial opening in the top wall of said inner member and formed with a head engageable with the top wall of the first-named annular member in the space between said top wall and the top wall of the inner member whereby to permit relative axial movement between said plunger and said piston, a driver connected to said plunger for reciprocation in said raceway, a resilient abutment in said cylinder engageable with said inner member to arrest the downward movement of the piston, and a spring seated in said cylinder and engageable with said inner member for raising the piston, plunger and driver after each stroke of the piston.

12. In a fluid-pressure operated fastener-applying machine comprising a raceway for fasteners and a cylinder connected to said raceway, a piston reciprocable in said cylinder, a fastener-driver connected to said piston for movement therewith and freely movable to a limited extent axially thereof, means to supply fluid-pressure to said cylinder to move said piston in one direction, means to arrest the movement of the piston prior to the completion of driving a fastener into the work whereby to cause the fastener-driver to extend its stroke under the force of momentum for completing the setting of the staple, and a spring engaging the piston without contact with said fastener-driver to return the piston and fastenerdriver to first position.

References Cited in the file of this patent UNITED STATES PATENTS Notice of Adverse Decision in Interference In Interference No. 90,536 involving Patent No. 2,888,679, H. F. Peterssen,

and E. I. Fisher, Fastener applying implement, final judgment adverse to the patentees was rendered Sept. 28, 1962, as to claim 1.

[Ofiioz'al Gazette January 29, 1.963.]

Disclaimer 2,8'88,679.Hem"y F. Peterssen and Edward 1. Fisher, -Westerly, RI. FAS- TENER APPLYING IMPLEMENT. Patent dated June 2, 1959. Disclaimer filed J an. 7 1963, by the assignee, Bostz'tch, Inc.

Hereby enters this disclaimer to claim 1 of said patent.

[Ofiieal Gazette Febm-afy 2-6, 1963.] 

